Nigerian citizens are required to have gained admission into a Korean approved university before moving ahead to apply for the D-2 visa. Certain visa types including C-type visas, such as Group Tourism (C-3-2), Medical Tourism (C-3-3), General Tourism (C-3-9), and Industrial Training (D-3), Non-Professional Employment (E-9), Vessel Crew (E-10), or Miscellaneous (G-1) visas cannot be converted into a D-2 visa. The application for student visa (D-2) requires a number of documents like the Certificate of Admission (CoA), which will be issued by the International Education Team at Korea University. D-2 visa (including D-2-6 and D-2-8) is a single entry only visa, with a 3 months validity period. Therefore, applicants must apply for a visa no more than 3 months prior to planned entry into South Korea. Nigerians are allowed to leave and re-enter Korea while maintaining a D-2 student status as long as they possess a valid Registration Card.